SOUTHEAST FLORIDA’S

RESILIENT WATER RESOURCESINCLUDING A CASE STUDY FOR THE CITY OF POMPANO BEACH

THE WATER INFRASTRUCTURE IN FLORIDA IS COMPLEX AND CAPITAL

INTENSIVE. MUCH OF IT WAS DESIGNED AND INSTALLED MORE THAN

50 YEARS AGO, LONG BEFORE CLIMATE CHANGE WAS CONSIDERED

A THREAT. SEA LEVEL RISE SINCE THEN IS ALREADY STRESSING THE

SYSTEM TODAY. SEA LEVEL IS PROJECTED TO RISE 3 TO 6 INCHES

ABOVE 2010 LEVELS BY 2030 AND 12 TO 21 INCHES BY 2060.

UP TO 70% OF THE DRAINAGE CAPACITY OF THE 28

COASTAL FLOOD/SALINITY CONTROL STRUCTURES

PROTECTING SOUTHEAST FLORIDA FROM FLOODING

AND SALTWATER INTRUSION COULD BE LOST WITH

SEA LEVEL RISE OF ONLY 3 TO 9 INCHES, ANTICIPATED

BY ABOUT 2030 TO 2050. ADAPTATION MAY REQUIRE

THE ADDITION OF HIGH-CAPACITY PUMPING STATIONS

COSTING APPROXIMATELY $70 MILLION EACH (PLUS

NECESSARY LAND ACQUISITIONS). THREE PUMPING

STATIONS COSTING A TOTAL OF OVER $200 MILLION

(PLUS LAND) COULD BE NEEDED IN NORTH MIAMI-

DADE COUNTY IN THE NEAR FUTURE.

CHANGES TO INFRASTRUCTURE

ARE REQUIRED TO PROTECT

FRESHWATER SUPPLIES,

DRAINAGE SYSTEMS, AND

VALUABLE ECOSYSTEMS,

AND TO PREVENT FLOODING

AND SEVERE ECONOMIC LOSSES.

SOUTHEAST FLORIDA’S WATER INFRASTRUCTUREIS VULNERABLE TO CLIMATE CHANGE

SOUTHEAST FLORIDA’S

NATURAL CHARACTERISTICS

LEAVE IT PARTICULARLY

VULNERABLE TO IMPACTS

OF CLIMATE CHANGE

SUCH AS SEA LEVEL RISE,

INCREASED LIKELIHOOD OF

EXTENDED DROUGHT, AND

TORRENTIAL RAIN EVENTS.

THE CASE STUDY FOR THE CITY OF POMPANO BEACH OUTLINES

ADAPTATION ALTERNATIVES FOR IMPROVING THE RESILIENCE OF THE

CITY’S WATER INFRASTRUCTURE. IMPLEMENTATION COULD REQUIRE

ESTIMATED CAPITAL EXPENDITURES OF UP TO $500 MILLION TO

$1 BILLION OVER THE NEXT 70 TO 100 YEARS, STARTING IN 2030.

HOUSEHOLD UTILITY BILLS COULD INCREASE BY AS MUCH AS $100

PER MONTH OR MORE. SIMILAR COSTS COULD BE INCURRED IN MOST

OF SOUTHEAST FLORIDA’S COASTAL COMMUNITIES.

EXPECTED CONSEQUENCES INCLUDE

REDUCED AVAILABILITY OF

DRINKING WATER AND INCREASED

RISK OF FLOODING DURING

MODERATE TO HEAVY RAIN EVENTS.

IMPLICATIONS OF THIS STUDY: THERE

IS A PRESSING NEED TO REASSESS

WATER RESOURCE PLANS WITH

RESPECT TO THE LATEST DATA ON

CLIMATE CHANGE, AND TO DEVELOP

AND IMPLEMENT ADAPTATION

STRATEGIES TO PREPARE FOR THE

LIKELY IMPACTS OF CLIMATE CHANGE.

THE SOONER THIS PROCESS IS

UNDERTAKEN, THE MORE EFFECTIVE,

LESS DISRUPTIVE, AND LESS COSTLY

IMPLEMENTATION WILL BE.

ADAPTIVE STRATEGIES INCLUDE

CONSERVING AND PROTECTING WATER

SUPPLIES, DEVELOPING ALTERNATIVE

WATER SOURCES, REUSING

WASTEWATER, AND REENGINEERING

STORMWATER SYSTEMS.

SOUTHEAST FLORIDA, WITH A POPULATION OF 5.5 MILLION,

IS RANKED AS ONE OF THE TEN MOST VULNERABLE

SOUTHEAST FLORIDA IS RANKED

AS ONE OF THE TEN MOST VULNERABLE COASTAL METROPOLITAN

AREAS IN THE WORLD.

2 | 3

SOUTHEASTFLORIDA’S

UNIQUE VULNERABILITY TO CLIMATE CHANGE

CHARACTERISTICS OF SOUTHEAST FLORIDA INCLUDE:

• a wide variation in seasonal rainfall, with dry winters and springs, and wet summers and autumns;

• high volumes of rainfall, of about 60 inches per year, equivalent to a total of 1 billion gallons per square mile per year, with 70% during the rainy summer and autumn seasons;

• periods of drought, especially during the dry winter and spring seasons;

• torrential rainfall, from thunderstorms, tropical storms, and hurricanes, especially during the wet season;

• low elevations, less than 5 feet above mean sea level in many areas (Figure 1);

• open water system, consisting of porous soil and an open coastal aquifer (the Biscayne Aquifer, Figure 2); and

• a vulnerable location, surrounded by the subtropical mid-Atlantic Ocean and the Gulf of Mexico.

SOUTHEAST FLORIDA’S RESILIENT WATER RESOURCES

Table 1. Range in Projected Sea Level Rise by 2100

YearProjected Sea Level Rise above 2010 Levels (feet)

2030 0.25 – 0.5

2060 1.0 – 1.75

2100 2.5 – 5.0

Figure 1. Low Elevations

The red areas of this map indicate parts of Southeast Florida that are below 3.28 ft (1 m) elevation above mean high tide, or about 5 ft above mean sea level. These regions could be at risk of serious fl ooding late in this century as sea level rises. [Credit: Weiss & Overpeck, Univ. Arizona]

40

SeaLevel

-40

-80

-120

-160

1,600 1,200 800 400 0 -400

Distance from Biscayne Bay (feet)

Elev

ation

(fee

t)

bedrock (base of aquifer)

Biscayne Aquiferporousrock freshwater

saltwater

dispersionzone

Biscayne Bay

The Biscayne Aquifer is the primary source of freshwater in Southeast Florida. This aquifer is unconfi ned and open to the Atlantic Ocean. Freshwater fl ows through the aquifer to the ocean, where it pushes against and mixes with saltwater in the dispersion zone.

Figure 2. Open Water System

SOUTHEAST FLORIDA’S RESILIENT WATER RESOURCES

4 | 5

WATER MANAGERS IN SOUTHEAST FLORIDA ARE

ALREADY FACING AGING INFRASTRUCTURE DESIGN AND

SALTWATER INTRUSION OF DRINKING WATER SUPPLIES.

1. AGING INFRASTRUCTURE:

2. SALTWATER INTRUSION OF DRINKING WATER SUPPLIES:

40

SeaLevel

-40

-80

-120

-160

1,600 1,200 800 400 0 -400

Distance from Biscayne Bay (feet)

Elev

ation

(fee

t)

bedrock (base of aquifer)

municipalwellfields

Biscayne Aquifer

freshwater pressure mustbe increased to preventsaltwater intrusion

increased saltwaterpressure due tosea level rise

dispersion zone

Biscayne Bay

As sea level rises, the pressure of saltwater on the dispersion zone increases, pushing saltwater further into the aquifer.

Figure 4. Salt Water Intrusion

Figure 3. Water Control System

A levee separates the Everglades, on the left, from an urban area on the right. An interstate highway runs up the center of the image.

WATER INFRASTRUCTURE IN SOUTHEAST FLORIDA

SOUTHEAST FLORIDA’S RESILIENT WATER RESOURCES

UNFORESEEN NEAR-TERM CHALLENGES DUE TO CLIMATE CHANGE

Figure 5. Challenges to Water System

increased periodsof drought

sea level rise

increased intensityof rainfall

decreased availability ofdrinking water

increased risk of floodingin low-lying inland areasduring major rain events

reduced groundwater flow

increasing saltwater intrusionof freshwater supplies

reduced capacity of floodcontrol structures

higher volumes ofstormwater

Impacts of Climate Change Issues Requiring SolutionsUnforeseen Challenges

Figure 6. Coastal Control Structures – % Capacity Remaining vs. Sea Level Rise

Sea level rise will reduce the capacity of flood control structures in Southeast Florida’s stormwater drainage canals.

110%

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0% 0 3 6 9 12 15 18 21 24

Sea Level Rise (inches)

% Ca

pacit

y Re

maining

100%

80%

69%

57%

31% 28%

16%

SOUTHEAST FLORIDA’S RESILIENT WATER RESOURCES

6 | 7

ADAPTATION MEASURES WILL BE EXPENSIVE

AND ENERGY-INTENSIVE. HOWEVER, THEY WOULD

PREVENT EVEN HIGHER COSTS DUE TO LOSSES.

1. TO PROTECT SUPPLIES OF FRESHWATER.

2. TO PREVENT FLOODING.

3. TO MAINTAIN DRAINAGE SYSTEMS.

4. TO PROTECT VALUABLE ECOSYSTEMS.

5. TO PREVENT SEVERE ECONOMIC LOSSES.

WHY CHANGES TO WATER INFRASTRUCTURE ARE REQUIRED

Figure 7. Torrential Rain

Heavy rainfall events are already common in Southeast Florida. Increased intensity of storms and rising sea level will increase the risk of fl ooding.

Figure 8. Endangered Species

The Everglades is home to endangered species including the Florida panther, the Everglades Snail Kite, and the Cape Sable Seaside Sparrow.

FIND A BALANCE BETWEEN RETAINING

AS MUCH FRESHWATER IN THE WATER

SYSTEM AS POSSIBLE, AND ALLOWING FOR

INCREASED QUANTITIES OF STORMWATER.

RECOMMENDATIONSAND CONCLUSIONS

FRESHWATER RESOURCES IN SOUTHEAST FLORIDA MUST BE

MAINTAINED IN ORDER TO OFFSET THE CONSEQUENCES

Table 2. Water Resource Adaptation AlternativesAdaptation Strategy Examples

Water conservation • encourage reduced water use (e.g., subsidize water-saving devices and enforce landscape watering restrictions)

Protection of existing water sources

• protect existing municipal wellfi elds and water control structures• relocate wellfi elds as necessary

Development of alternative water sources

• desalinate brackish waters• capture and store stormwater

Wastewater reclamation and reuse

• use treated wastewater (e.g., for irrigation, industrial use, and to recharge aquifers)

Stormwater management • re-engineer canal systems, fl ood control structures, and pumps

• store excess water underground using aquifer storage and recovery (ASR)

SOUTHEAST FLORIDA’S RESILIENT WATER RESOURCES

8 | 9

CONCLUSIONS

RECOMMENDATIONS FROM THIS STUDY

1. Re-evaluate current policies and incorporate climate change into all water resource planning.

2. Bring scientists, engineers, water managers, and decision-makers together to work on the incorporation of climate change into water resource management plans.

3. Quantitatively evaluate the vulnerability of fl ood control structures and stormwater drainage systems. Develop plans for enhancement.

4. Assess and evaluate the impacts of climate change on groundwa-ter supplies. Develop plans to protect freshwater supplies and to develop alternative water sources.

5. Develop and implement increased freshwater storage and conservation to protect against water shortages due to drought or other causes.

6. Determine the increases in electric power supplies that will be needed in order to implement adaptation plans.

LIMITATIONS OF THIS STUDY

1. Limitations in climate change projections: The main uncertainty when predicting the effects of climate change is the possible range of human choices regarding energy policy and land use in the future. For this reason, projected impacts are based on a range of scenarios.

2. Limitations in projections of sea level rise and other climate change impacts: When predicting sea level rise and other potential impacts of climate change, a key uncertainty is the potential for positive climate feedbacks due to reduced ice cover, melting perma-

frost, increased humidity, etc., and the possibility that irreversible thresholds may be crossed. These could dramatically increase the rate and extent of glacial melting and sea level rise.

3. Limitations in projections on impacts on Southeast Florida’s water systems: Extensive research and integrated hydrologi-cal modeling is required to predict the effects of climate change impacts on Southeast Florida’s water systems more accurately, and to test alternative solutions.

THE CITY OF POMPANO BEACH IS LOCATED IN

NORTHEAST BROWARD COUNTY, FLORIDA.

CASE STUDYADAPTATION STRATEGIES FOR THE CITY OF POMPANO BEACH WATER UTILITY

SEA LEVEL RISE IS THE

MOST SIGNIFICANT CLIMATE CHANGE

ISSUE FACED BY THE

CITY OF POMPANO BEACH

Figure 9. The City of Pompano Beach

SOUTHEAST FLORIDA’S RESILIENT WATER RESOURCES

10 | 11

Figure 10. The Atlantic Intracoastal Waterway runs from Key West, Florida, to Norfolk, Virginia

Figure 11. Water treatment plant in the City of Pompano Beach

SOUTHEAST FLORIDA’S RESILIENT WATER RESOURCES

VULNERABILITY TO DROUGHT AND HEAVY RAINFALL EVENTS

VULNERABILITY TO INCREASED INTENSITY OF STORMS

VULNERABILITY TO SEA LEVEL RISE

CHALLENGES FACING THE CITY OF POMPANO BEACH

ASSESSMENT OF ENGINEERED SOLUTIONS AND COSTS

POTENTIAL VULNERABILITIES TO THE IMPACTS OF CLIMATE CHANGE

Figure 12. Fallen trees can damage the water distribution system.

Table 3: Recommended Strategies and Estimated Costs

Sea level rise Recommended strategy Estimated cost

Near-term (by 2030)

0-0.5 ft

1. Eliminate trees in rights-of-way to avoid storm damage. $ millions (requires assessment)

2. Upgrade water plant equipment to prevent failure from storm damage.depends on results of engineering studies

3. Install pump stations in low-lying areas to reduce stormwater flooding

Pump station

start at $1.5 to 5 million per station

4. Encourage water conservation.$40 million over first 10 years + $1 million/yr thereafter

5. Repair and upgrade the sewage system.start at $12.5 million, plus annual cost

(2030 to 2060)

0.5-1 ft

6. Reuse wastewater for irrigation to reduce consumption of groundwater. over $25 million

7. Use reclaimed wastewater to recharge aquifers, offsetting saltwater intrusion.

Treated wastewater can recharge the aquifer in human-made wetlands

up to $200 million

(2040 to 2070)

1-2 ft

8. Treat saltwater and brackish water to produce drinking water.

Reverse Osmosis Water Treatment Facility

$45-50 million

9. Install additional pump stations to control flooding in inland flood plains.start at $1.5-5 million each (would need at least 12)

10. Install a sewage system to replace inoperative septic systems.assessed against property own-ers at $10,000 each; total cost under $20 million

11. Close private irrigation wells to conserve water. Encourage use of recovered wastewater.depends on results of engineer-ing studies

12. Relocate wellfields. $20 million

13. Install salinity control structures to significantly reduce saltwater intrusion.up to $10 million, may require additional pumping stations at $2-5 million each

(2070 to 2100)

before 3 ft

14. Inject reclaimed wastewater into brackish aquifers.

A typical aquifer storage and recovery (ASR) wellhead

$30 million for wells and piping, unknown for water treatment

(2080 to >2100)

3-4 ft 15. Implement major renovation of flood control systems. Consider treating and discharging excess water into the Everglades.

$ billions

(2100)

greater than 4 ft

16. Prepare for low-lying areas of the city to be abandoned (worst-case scenario). $ billions

17. Implement a large-scale system of dikes (worst-case scenario). $ billions